DE19713688B4 - Rolling bearing with a displacement measuring device - Google Patents

Abstract

Rolling bearing with a device for measuring the distance covered by a movable rolling bearing part with respect to a fixed rolling bearing part having a measuring range with at least one sensor, which is provided for the contact or non-contact scanning of one of the bearing components and arranged on one of the rolling bearing parts, wherein the sensor respectively is directed to one of the supporting rolling elements, which are located between the fixed rolling bearing part and the movable rolling bearing part and during the movement of the movable rolling bearing part past the sensor, characterized in that in the load zone of the measuring range, a plurality of sensors (10) are integrated, each capture the same rolling element.

Description

Field of the invention

The The invention relates to a rolling bearing with a device for measuring the movement of a rolling bearing part across from a fixed rolling bearing part traveled Weges, which has a measuring range with at least one sensor, the for the touching one or non-contact Scanning one of the bearing components provided and on one of the rolling bearing parts is arranged, wherein the sensor in each case on one of the supporting Directed rolling element, which is between the fixed bearing part and the movable rolling bearing part are located and while the movement of the movable rolling bearing part roll past the sensor.

Background of the invention

Such a rolling bearing with a path measuring device is known from the international patent application with the publication number WO 91/16594 known. There, the movable, the measuring range containing the sensor bearing component is designed as a roller circulation unit and the fixed rolling bearing part as a guide rail of a linear roller bearing, on which the roller circulation unit is supported via the supporting rollers designed as rolling bearing. This bearing requires a scale on the guide rail, which is exposed to the environment as an optical or magnetic scale, is thus sensitive to the action of dirt and can be easily damaged. The required additional processing of the guide rail for attaching the material measure is expensive and makes the rail softer, so that when Belas tion greater elastic deformation occurs. The measuring head on the roller circulating unit acting as a guide carriage must be specially sealed and the measuring graduation in the measuring head area must be stripped so that no dirt such as chips, dust, coolant or lubricant impairs the measurement.

From the publication DE-AS 22 18 047 is a rolling bearing with a device for measuring the distance traveled by a movable rolling bearing against a fixed rolling bearing part way by measuring the speed known. The movable rolling bearing part is a circumferential inner ring and the fixed rolling bearing part is a solid outer ring. Between the rings are as bearing rolling elements balls. On the fixed rolling bearing part is a seal and attached to this as a sensor means for generating a magnetic field and for sensing the change of the magnetic field. As the inner ring rotates, the balls traverse the magnetic field producing pulses in the device which are transmitted via a line for evaluation.

The publication US 5 026 178 shows a trained as a radial ball bearing Rotativlager of the aforementioned type, in which two or three Hall effect sensors are arranged by a first Hall effect sensor at intervals in the circumferential direction one behind the other, which corresponds to a certain factor of the distance between two adjacent balls. In this case, in the load zone, a sensor is directed in each case to one of the supporting rolling elements.

Summary of the invention

Of the Invention is based on the object, a rolling bearing with a displacement measuring device to create, which has a simple technical structure and opposite the impact of dirt insensitive than known such bearings is.

These Task is inventively characterized solved, that several sensors are integrated in the load zone of the measuring range are that each capture the same rolling elements. That way, the resolution can be the measurement can be improved and you also receive information about the Movement.

There at execution of the bearing as a linear roller bearing with a fixed guide rail and a movable support body the rolling element movement in the load zone of the bearing in unambiguous connection with the movement of acting as a supporting body movable rolling bearing part stands, can from the rolling element movement on the support body movement getting closed. So if the rolling element movement is detected, can the material measure and the extra Sealing the linear roller bearing omitted.

It is possible, too, at a rolling bearing with a displacement measuring device, the measuring range on the fixed rolling bearing part to arrange. For example, the movable rolling bearing part as an inner ring and the fixed, containing the measuring range with the sensor rolling bearing part as outer ring a radial ball bearing be formed, on which the inner ring on the supported as balls bearing supporting rolling elements is supported.

With suitable sensors, the position of the respective rolling element is detected. at the movement of the camp is running a rolling element on a sensor over. This emits a sinusoidal signal, by an evaluation in a value for the Tragkörper- or Bearing ring movement can be converted.

Of the Measuring range can several, for example three directed to the supporting rolling elements Sensors included. If several rolling elements of a rolling element circulation, z. B. in a single-row deep groove ball bearing, or more different Wälzkörperumläufe, z. B. in profiled rail guides, detected in this way, so can the measurement accuracy significantly increased be that means a "smart" electronics error such as pitch end play or slip detected and in addition the different measured values be interpolated. To measure the sensor position, a capacitive, an inductive, a touching Measuring principle or it can other measuring principles chosen become. When choosing suitable miniature sensors, these can even in the raceways, z. B. in the inlet region of the rolling elements in Profile rail guides, be housed without the function and space of the bearings to influence that can be serial production.

Brief description of the drawings

embodiments The invention are illustrated in the drawings and will be described in more detail below. They show schematically:

1 a linear roller bearing with sensors in the side view;

2 the roller circulating unit of the bearing 1 in the bottom view;

3 the course of the signals on the travel, the three sensors of the camp after 1 to be delivered;

4 a trained as a radial ball bearing Rotativlager with sensors in axial view;

5 the warehouse after 4 in radial view;

6 a previously known linear bearing with a displacement measuring device in the frontal view;

7 the warehouse after 6 in the side view.

Detailed description of the drawings

In a rolling bearing with a distance measuring device according to the prior art, the distance covered or angle of the movable rolling bearing part can be determined with a measuring head mounted there, which is moved along a arranged on the fixed rolling bearing part measuring scale. The 6 and 7 show this a solid guide rail 1 with a side-mounted scale 2 , At one along the guide rail 1 movable carriage 3 is a measuring head 4 attached, the procedure of the carriage 3 along the guide rail 1 on the scale 2 driving along. The scale 2 For example, it may carry an optical bar code or a partial magnetization. The measuring head 4 carries a sensor. When passing the scale 2 the measuring head delivers 4 a signal about the distance traveled.

such measurement methods are relative, d. H. the material measure gives no information about the absolute position but only about the way over or at a Rotativlager over the angle. If you want to measure an absolute position, you need it a reference point that is approached once after switching on and defined as "zero point". The Distance measurement then takes place relative to this point.

The inventive wegmessende bearings also provides relative readings. The reference point must also be approached externally here. The difference to the state of the art lies in the fact that in waived the new bearing on a material measure becomes. The information about the traveled The way will be not from the relative movement carriage rail or inner ring outer ring obtained, but from the relative movement carriage-rolling elements or Ring rolling elements.

The 1 and 2 show a linear roller bearing 5 with a guide rail 6 and a roller circulating unit supported thereon 7 , This contains in a carriage 8th rotating rollers 9 as a rolling element and three in the direction of travel of the guide rail 6 successively arranged sensors 10 that are inside the carriage 8th on carrying roles 9 are directed.

In the load zone of the rollers 9 These move relative to the carriage 8th at half the speed of the carriage. This movement is defined by the fixed clamping between the tracks and thus contains information about the movement of the carriage 8th , Now, if the Wälzkörperstellung is detected in this load zone by a suitable sensor, it can be calculated from the distance traveled by the movable rolling bearing part.

The sensors 10 in the outlined role circulation according to 1 and 2 detect the rolling element position. Optical, magnetic, inductive, capacitive or ohmic transducers are conceivable for this measurement. The sensors 11 each touch the lateral surfaces of the rollers without contact 9 and deliver a signal, as z. In 3 is shown. Capacitive, inductive or optical sensors can be based on the distance to the lateral surface of the respective roll 9 other optical sensors may deflect a light beam through the roller jacket, ohmic or piezo sensors can measure the material deformation depending on the roller position. From the measured values obtained, the distance covered can be calculated directly. The solution according to the invention, according to which a plurality of sensors are integrated in a load zone, each of which detects the same rolling element, is for example in the 1 and 2 outlined.

The 4 and 5 show a Rotativlager, in which sensors 10 are integrated in a similar manner as in the linear roller bearing 5 to 1 This bearing is as a radial ball bearing 11 with an inner ring 12 an outer ring 13 and balls in between 14 designed as rolling elements. Three sensors 10 are in the outer ring 13 attached and on the passing balls 14 directed.

Contains a warehouse several rows of rolling elements, so you can do this in addition record and calculate the values obtained. This approach allows a detection and elimination of measurement inaccuracies such as slippage or Pitch final. In this way, the measurement accuracy can be essential elevated become.

Of the Advantage of the invention wegmessenden roller bearing on the one hand consists of the omission of a material measure and on the other hand The possibility, all possible Sensor types, such as capacitive, inductive, optical, magnetic or ohmic sensors. As you know, especially the Integration of a material measure in a guide rail or a bearing ring disadvantages such as a stiffness loss and a cause problematic and expensive production, - with integrated scale is an editing of the guide rail by cleats not possible, - poses the wegmessende invention roller bearing a cheap, flexible and technically easy to implement alternative to previously known roller bearings represents.

1

guide rail

2

scale

3

carriages

4

measuring head

5

Linear roller bearings

6

guide rail

7

Roller monorail

8th

carriages

9

role

10

sensor

11

Radial ball bearings

12

inner ring

13

outer ring

14

Bullet

Claims (5)

Rolling bearing with a device for measuring the distance covered by a movable rolling bearing part with respect to a fixed rolling bearing part having a measuring range with at least one sensor, which is provided for the contact or non-contact scanning of one of the bearing components and arranged on one of the rolling bearing parts, wherein the sensor respectively is directed to one of supporting rolling elements, which are located between the fixed bearing and the movable bearing part and roll past during the movement of the movable bearing member to the sensor, characterized in that in the load zone of the measuring range (several sensors 10 ) are integrated, each detecting the same rolling elements. Rolling bearing according to claim 1, characterized in that the movable rolling bearing part the measuring range with the sensors ( 10 ) and as a roller circulation unit ( 7 ), and the fixed rolling bearing part as a guide rail ( 6 ) of a linear roller bearing ( 5 ) is formed, on which the roller circulation unit ( 7 ) about as roles ( 9 ) supported supporting rolling elements is supported. Rolling bearing according to claim 1, characterized in that the movable rolling bearing part as an inner ring ( 12 ) and the fixed rolling bearing part as outer ring ( 13 ) of a radial ball bearing ( 11 ) is formed, on which the inner ring ( 12 ) about as balls ( 14 ) supported supporting rolling elements, wherein the fixed rolling bearing part of the measuring range with the sensors ( 10 ) contains. Rolling bearing according to claim 1, characterized in that each sensor ( 10 ) is connected to an electronic computer for the evaluation of its signals. Rolling bearing according to claim 1, characterized in that the measuring range three directed to the supporting rolling elements sensors ( 10 ) contains.